Smart Wireless Power/Data Transfer System

ABSTRACT

A system for providing electrical power to a remote device through wireless transmission is provided. The system includes a power transmitting data unit (PTDU), at least one power receiving data unit (PRDU) and at least one power throttling circuit. The PTDU receives electrical power from a power source. The PRDU is connected to a load device. The PRDU includes a resonator and a power conversion circuit. The resonator receives electromagnetic waves from the PTDU and converts the electromagnetic waves into the electrical power. The power conversion circuit provides target power to the load device. The power throttling circuit determines how much electrical power from the resonator needs to be transmitted to the power conversion circuit based on the power requirement of the load device, wherein the electrical power required for the load device is regarded as the target power.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is a Continuation-In-Part of pending U.S. patentapplication Ser. No. 16/385,949, filed on Apr. 16, 2019, which claimspriority of U.S. Provisional Patent Application 62/788,194, filed onJan. 4, 2019. The entirety of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention generally relates to electrical power delivery,and more specifically to a wireless power delivery system.

Description of the Related Art

Traditionally electrical power is delivered by connecting physically adevice to an electrical grid and in recent years new system has beendeveloped to deliver electrical power through electromagnetic induction.For wireless power transfer, non-radiative technique is generally usedand the power is transferred over short distances by magnetic fieldsthrough inductive coupling or electric field through capacitivecoupling. The transmission of electrical power through electromagneticinduction involves two devices, one is an electromagnetic wavetransmitter and other is an electromagnetic wave receiver. Theelectrical power is transmitted by the electromagnetic wave transmitteras an electromagnetic wave through the air or through another medium andis received and converted back into electrical power by theelectromagnetic wave receiver. Each of the transmitter and the receiverincludes a resonator operating at a certain frequency. The effectivetransmission of the power requires the frequencies used in the resonatorin the transmitter and the resonator in the receiver to be the same orwithin a narrow band of each other.

This requirement of the operating frequencies to be the same or within anarrow band places a limitation on the wireless power transfer. Hence,it is imperative to devise a system that improves the wireless powertransfer.

SUMMARY OF THE INVENTION

An embodiment of the invention provides a system for providingelectrical power to a load device through wireless transmission. Thesystem comprises a power transmitting data unit (PTDU), at least onepower receiving data unit (PRDU) and at least one power throttlingcircuit. The PTDU receives electrical power from a power source. ThePRDU is connected to the load device. The PRDU comprises a resonator anda power conversion circuit. The resonator receives electromagnetic wavesfrom the PTDU and convers the electromagnetic waves into electricalpower. The power conversion circuit provides the target power to theload device, wherein the electrical power required for the load deviceis regarded as the target power. The power throttling circuit determineshow much electrical power from the resonator needs to be transmitted tothe power conversion circuit based on the power requirement of the loaddevice.

An embodiment of the invention provides a method for providingelectrical power to a load device through wireless transmission, whereinthe method is applied to a system which comprises a power transmittingdata unit (PTDU), at least one power receiving data unit (PRDU) and atleast one power throttling circuit. The method comprises the followingsteps. In the first step, the resonator of the PRDU receives theelectromagnetic waves from the PTDU and converts the electromagneticwaves into electrical power. In the second step, the power throttlingcircuit determines how much electrical power received by the resonatorneeds to be transmitted to a power conversion circuit of the PRDU basedon the power requirement of the load device, wherein the electricalpower required for the load device is regarded as a target power. In thethird step, the power conversion circuit provides the target power tothe load device.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become better understood from a careful readingof a detailed description provided herein below with appropriatereference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be understood in more detail by reading thesubsequent detailed description in conjunction with the examples andreferences made to the accompanying drawings, wherein:

FIG. 1 is architecture 100 of a system according to the invention;

FIG. 2 is an illustration 200 of the interface between a PTDU and aPRDU;

FIG. 3 is another embodiment 300 of the interface between a PTDU and aPRDU;

FIG. 4 is a schematic model 400 for wireless power transfer;

FIG. 5 is a flow chart 500 for identifying a foreign object;

FIG. 6 is a flow chart 600 illustrating the interaction between a PTDUand a PRDU;

FIG. 7 is a diagram 700 for one embodiment of the PTDU;

FIG. 8 is a diagram 800 for one embodiment of the PRDU;

FIG. 9 is a flowchart 900 for initial positioning;

FIG. 10 is a flowchart 1000 for adjusting driving parameters ofelectromagnetic waves;

FIG. 11 is an illustration 2000 of the interface between a PTDU and aPRDU according to another embodiment of the invention.

FIG. 12 is a schematic diagram of bidirectional sharing mechanismaccording to an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In essence, the present invention is a high efficiency smart wirelesspower/data transfer system that has a high tolerance for resonatorfrequency variation, load variation, distance variation. The presentinvention also introduces methods for aiding physical alignment betweena transmitter and a receiver and for detecting foreign objects in asetting for power transfer. The present invention enables cost effectiveimplementation of a highly scalable and efficient wireless power/datatransfer system. Through continuous data exchange with targeted devicesand creation of a profile (or power profile) for each device, the systemaccording to the present invention can tailor each wireless powertransfer according to the characteristics of the devices and also thephysical environment.

FIG. 1 shows architecture 100 of a system to transfer power wirelesslyaccording to the present invention. The electrical power is transferredwirelessly from a power source (not shown) connected to a PowerTransmitting Data Unit (PTDU), 112, 114 to a Power Receiving Data Unit(PRDU) 106, 108 to which devices 102, 104 are connected. For portabledevices, such as smart phones, the PRDU 106, 108 may be built into thesmart phones. For devices, such as home appliances or factorymachineries, the PRDU 106, 108 may be separated from the devices and thepower may be transmitted through a wire or a cable from the PRDU 106,108 to the home appliances.

Besides transferring the power to the devices 102, 104, the data canalso be exchanged through a data link between the devices 102, 104 andthe PRDU 106, 108. The data from the devices 102, 104 may be theidentification data from the devices 102, 104. The data may also becoming from the PRDU 106, 108 and this data represent the status ofwireless transfer (current/voltage drawn by the devices 102, 104) fromthe PRDU 106, 108. The PRDU 106, 108 sends and receives data from thePTDU 112, 114. The data link between the PRDU 106, 108 and the PTDU 112,114 is through wireless communication. One example of such wirelesscommunication is through the ISM band (industrial, scientific, andmedical radio band) and the data is transferred through out-of-bandcommunication. It is understood that other communication protocol mayalso be used for the communication between the PTDU and the PRDU. When aPTDU is located far away from a PRDU, for the wireless power transfer towork properly, a Repeater Unite (RU) 110 may be used. The RU 110receives the power from the PTDU 112 and transmits to the PRDU 106. TheRU 110 also supports two way communications and relays the data betweenthe PTDU 112 and the PRDU 106. It is understood that other wirelesscommunication means may also be used to support the data link betweenthe PTDU and PRDU.

The data link between the PRDU 106, 108 and the PTDU 112, 114 alsoenables the device 102, 104 to send and receive data to and from theInternet 120. While the device 102, 104 is connected to the PTDU 112,114 through the PRDU 106, 108, an application running on the device canreach the Internet through the data link between the PTDU and PRDU to aserver on the Internet 120.

The data from the device 102, 104 may be identification data that isexchanged between the device 102, 104 and the PTDU 112, 114 when thedevice 102, 104 is first connected to the system. The PTDU 112, 114 willretrieve a profile (or power profile) associated with the device 102,104 and the profile may contain setup information for the device 102,104 and the associated PRDU 106, 108 and PTDU 112, 114. The PTDU 112,114 may also create a profile for the device 102, 104 if there is noprofile found for the device 102, 104. The data received from the PRDU106, 108 during the power transfer may contain status informationrelated to the power transfer and the PTDU 112, 114 continuously monitorthese data. The profile may contain the identification data for adevice, the setup information for the PRDU, and the past power transferinformation. The identification data may be collected from the deviceand may be used for setting up the device, while the power transferinformation may be received from the PRDU. Through continuous monitoringof these data, the PTDU 112, 114 may detect problems at the device 102,104 and may adjust the driving parameters of the PTDU 112, 114.

The data (except the user data from the applications running on thedevices) received from the device 102, 104 are saved in a profile (orpower profile). The profile for each device may be stored in a localserver or a remote server 124. The remote server 124 may serve as apower-profile artificial-intelligence (AI) engine that processes thedata (except the user data) received from the devices 102, 104 and thePRDU 106, 108. The connection from the PTDU 112, 114 to the remoteserver 124 may be through a gateway/router 116 and the Internet 120.Alternatively, the PTDU 112, 114 may be connected to the remote server124 through a smart device 118 and the Internet 120. In an embodiment ofthe invention, all of the power profiles can be shared by the remoteserver 124 and one or more PTDUs (e.g. PTDU 112 and PTDU 114). That isto say, the power profiles obtained by the remote server 124 can beshared with PTDU 112 and PTDU 114, and the power profiles obtained byPTDU 112 and PTDU 114 can be shared with the remote server 124. Thebidirectional sharing for the power profiles may improve the powerdelivery efficiency. In an embodiment of the invention, each PTDU (e.g.PTDU 112 and PTDU 114) may comprise a power-profile AI engine to obtainthe power profiles. As shown in FIG. 12, the PTDU 112 may have apower-profile AI engine 1121 and the PTDU 114 may have a power-profileAI engine 1141. The computing capability of the power-profile AI engine(e.g. the power-profile AI engine 1121 and the power-profile AI engine1141) of the PTDU may be lower than the computing capability of theremote server 124. In an embodiment of the invention, the power profilesobtained by the power-profile AI engine 1121 of the PTDU 112 may beshared with the power-profile AI engine 1141 of the PTDU 114 via theremote server 124. In addition, the power profiles obtained by thepower-profile AI engine 1141 of the PTDU 114 may be shared with thepower-profile AI engine 1121 of the PTDU 112 via the remote server 124.

By receiving the data from the devices 102, 104 and from the PRDU 106,108, and the environment variables sensed by the PTDU, 112, 114, thesystem of the present invention will be able to detect foreign objectsthat may be present in the environment. Foreign objects refer tometallic objects that may be heated when exposed in an electromagneticfield, thus reducing the efficiency of power transfer and creating adangerous situation. The recognition of the foreign objects can be donethrough a foreign object detection (FOD) AI engine 122 in the remote endby processing the data received from either the devices 102, 104, fromthe PRDU 106, 108, or the environment variables sensed by the PTDU 112,114. The recognition of the foreign objects improves over time as moredata are received from the PRDU 106, 108 and the devices 102, 104 or theenvironment variables sensed by the PTDU 112, 114. The recognition ordetection of foreign objects also can be done through PTDU 112 and PTDU114. In an embodiment of the invention, all information related to therecognition or detection of foreign objects can be shared by the FOD AIengine 122 and one or more PTDU (e.g. PTDU 112 and PTDU 114). That is tosay, the information related to the recognition or detection of foreignobjects obtained by the FOD AI engine 122 can be shared with PTDU 112and PTDU 114, and the information related to the recognition ordetection of foreign objects obtained by PTDU 112 and PTDU 114 can beshared with the FOD AI engine 122. The information related to therecognition or detection of foreign objects may comprise the machinelearning results, the training data of the machine learning algorithms,the settings and parameters of the machine learning algorithms, but theinvention should not be limited thereto. The bidirectional sharing forthe information related to the recognition or detection of foreignobjects may improve the detection and prediction accuracy. In anembodiment of the invention, each PTDU (e.g. PTDU 112 and PTDU 114) maycomprise a FOD AI engine to perform the recognition or detection offoreign objects. As shown in FIG. 12, the PTDU 112 may have a FOD AIengine 1122 and the PTDU 114 may have a FOD AI engine 1142. Thecomputing capability of the FOD AI engine (e.g. the FOD AI engine 1122and the FOD AI engine 1142) of the PTDU may be lower than the computingcapability of the FOD AI engine 122 in the remote end. In an embodimentof the invention, the information related to the recognition ordetection of foreign objects obtained by the FOD AI engine 1122 of thePTDU 112 may be shared with the FOD AI engine 1142 of the PTDU 114 viathe FOD AI engine 122. In addition, the information related to therecognition or detection of foreign objects obtained by the FOD AIengine 1142 of the PTDU 114 may be shared with the FOD AI engine 1122 ofthe PTDU 112 via the FOD AI engine 122.

FIG. 2 is an illustration 200 of interface between a PTDU 114 and a PRDU108. The PRDU 108 receives electrical power through electromagneticwaves from the PTDU 114 and supplies the electrical power to a device104. The PRDU 108 has a resonator 204, an AC/DC power converter 202, acontroller (not shown), and a communication unit 206. The resonator 204receives and converts the electromagnetic waves into alternating current(AC) and this AC is converted into a direct current (DC) by the AC/DCconverter 202. The DC is then made available to the device 104. The DCmay be used directly by the device 104 or it may be used to charge astorage unit inside the device 104. The communication unit 206 sends andreceives data to and from the device 104. The communication unit 206also sends the data received from the device 104 to the PTDU 114 and thedata is sent wirelessly to the PTDU 114 as out-of-band communication.

The PTDU 114 receives electrical power from a power source and transmitsthe power through electromagnetic waves to the PRDU 108. The PTDU 114has a resonator 210, a DC/AC power converter 212, a controller (notshown), and a communication unit 208. The DC/AC power converter 212converts the DC to AC that drives the resonator 210. The PTDU 114 alsomay receive the AC directly. The resonator 210 receives the AC andgenerates electromagnetic waves. The communication unit 208 receives thedata transmitted wirelessly by the PRDU 108. There are basically twotypes of data exchanged between the PTDU 114 and the PRDU 108: powercontrol information and user data. The PTDU 114 sends the power controldata to the PRDU 108, so the PRDU 108 can be properly set up for thepower transfer. The PRDU 108 sends the status information back to thePTDU 114. The user data being from the applications running on thedevice 104 are sent from the PRDU 108, through the PTDU 114, to serversconnected to the Internet.

The resonators 204 in the PRDU 108 have a resonant frequency f2 and theresonator 210 in the PTDU 114 has a resonant frequency f1. The resonantfrequency f1 may be different from the resonant frequency f2. Theresonator 210 in the PTDU 114 is driven by a voltage VPA from the DC/ACpower converter 212 operating at frequency fs. The PTDU 114 candetermine a best operating frequency fs for the DC/AC power converter212, such that there is no relationship between the frequencies f1 andf2, the frequency fs is independent from frequency f1, and the frequencyfs is higher than frequency f2.

Traditionally the power transfer between the PTDU 114 and the PRDU 108is through resonant inductive coupling, where the resonators in the PTDU114 and the PRDU 108 are tuned to resonate at a resonant frequency andthe resonant frequency is the same as or close to the resonant frequencyof each PTDU and PRDU. The smart algorithm, introduced by the presentinvention, running on the PTDU 114 can find the best operating frequencyfs, along with proper adjustment of the driving voltage VPA and thedriving frequency to deliver power with good system efficiency and thereis no requirement for the operating frequency (also known as drivingfrequency) fs to be close to or the same as the resonant frequencies f1and f2. The operating frequency fs is independent of the resonantfrequency f1 and also higher than the resonant frequency f2. Thisalgorithm can handle dynamic load change and distance change byadjusting the operating frequency fs and/or driving voltage VPA.

FIG. 3 is another embodiment 300 of the interface between a PTDU and aPRDU and also a simple schematic representation of wireless powertransfer between two ports. The communication units in both the PTDU 304and the PRDU 302 are omitted for simplicity, however, the data exchangeexists between the PTDU 304 and the PRDU 302. The components within thePTDU 304 and within the PRDU 302 functions as previously described. TheRU 314 is employed when the PRDU 302 is physically located at a greaterdistance from the PTDU 304.

With or without the RU 314, the efficiency of the power transfer betweenthe PTDU 304 and the PRDU 302 depends on the impedances of atransmitting port (Port 1) and a receiving port (Port 2), and thetransfer impedance. The transfer between the PTDU 304 and the PRDU 302,as represented by box 316, and the impedances can be expressed asfollows.

Z ₁₁ =R ₁₁ ±jX ₁₁

Z ₁₂ =R ₁₂ +jX ₁₂

Z ₂₁ =R ₂₁ +jX ₂₁

Z ₂₂ =R ₂₂ +jX ₂₂

wherein

Z=R+jX means Impedance (Z)=Resistance (R)+j*Reactance (X).

Z₁₁=Impedance seen at Port 1, Z₁₂=transfer impedance from Port 2 to Port1;

Z₂₂=Impedance seen at Port 2, Z₂₁=transfer impedance from Port 1 to Port2;

R₁₁=Resistance seen at Port 1, R₁₂=transfer Resistance from Port 2 toPort 1;

R₂₂=Resistance seen at Port 2, R₂₁=transfer Resistance from Port 1 toPort 2;

X₁₁=Reactance seen at Port 1, X₁₂=transfer Reactance from Port 2 to Port1;

X₂₂=Reactance seen at Port 2, X₂₁=transfer Reactance from Port 1 to Port2.

The Z matrix above is a general 2 port model and can represent anysystem. In a general context, it represents PTDU resonator and PRDUresonators and everything between them. Thus, it could mean anycircuitry, mechanical housing, air, wood, glass sitting, and othermedium between PTDU resonator and PRDU resonator. The Rij, Zij, and Xijrepresent part of the resonators PTDU and PRDU and everything betweenthem.

From the above, the efficiency can be expressed as follows.

$\begin{matrix}{{Eff} = \frac{\left( {{{RL}.R_{12}^{2}} + {{RL}.X_{12}^{2}}} \right)}{\begin{matrix}\begin{matrix}{{\left( {{- R_{22}} - {RL}} \right).R_{12}^{2}} + {\left( {{{- 2.}{X_{12}.X_{22}}} - {2.X_{12}{XL}}} \right).}} \\{R_{12} = {{R_{11}.R_{22}^{2}} + {2.{R_{11}.R_{22}^{2}}} + {2.{R_{11}.R_{22}.{RL}}} +}}\end{matrix} \\{{R_{22}.X_{12}^{2}} + {R_{11}.{RL}^{2}} + {{RL}.x_{12}^{2}} + {R_{11}.X_{22}^{2}} +} \\{{2.{R_{11}.X_{22}.{XL}}} + {R_{11}.{XL}^{2}}}\end{matrix}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

RL=load resistance;

XL=load reactance.

For a lossless coupling when R12=0, the efficiency is as follows.

${Eff}_{0\; R\; 12} = \frac{{RL}.X_{12}^{2}}{\begin{matrix}{{R_{11}.R_{22}^{2}} + {R_{11}.{RL}^{2}} + {R_{11}.X_{22}^{2}} + {R_{22}.X_{12}^{2}} + {R_{11}.{XL}^{2}} +} \\{{{RL}.X_{12}^{2}} + {2.{R_{11}.R_{22}.{RL}}} + {2.{R_{11}.X_{22}.{XL}}}}\end{matrix}}$

The wireless power transfer between two ports as shown in FIG. 2 can besimplified by a schematic representation 400 shown in FIG. 4 inconjunction with FIG. 3. The schematic representation 400 is known as“transformer+series capacitance” model. The optimum w (angularfrequency) that supports the maximum efficiency in this model can beobtained as follows. Note that w=2πf (angular frequency=2. π.frequency).

${{w\_ opt}{\_ OR}\; 12} = \begin{pmatrix}{{root}\mspace{11mu}\left( {{\alpha 1},Z,1} \right)} \\{{root}\mspace{11mu}\left( {{\alpha 1},Z,2} \right)} \\{{root}\mspace{11mu}\left( {{\alpha 1},Z,3} \right)}\end{pmatrix}$

where

α₁ =L ₂ XLZ ³+2R ²² RLZ ²−2L ₂ ² w ₂ ² Z ² +XL ² Z ² +RL ² Z ² +R ₂₂ ² Z²−3L ₂ XLw ₂ ² Z+2L ₂ ² w ₂ ⁴

Root (α₁, Z, K): represent roots of a polynomial;

α₁: the polynomial;

Z: variable Z;

K: the Kth root of the polynomial;

$\mspace{20mu}{{z\; 1} = {- \frac{\begin{matrix}{{2\; R_{22}{RL}} + \sigma_{1} + \frac{\sigma_{2}^{2} + {9L_{2}^{2}{XL}^{2}w_{2}^{2}}}{\sigma_{1}} +} \\{R_{22}^{2} + {RL}^{2} + {XL}^{2} - \sigma_{3}}\end{matrix}}{3L_{2}{XL}}}}$${{Where}\mspace{14mu}\sigma_{1}} = \begin{pmatrix}{\frac{\sqrt{27L_{2}^{2}{{XL}^{2}\begin{pmatrix}{{108\; L_{2}^{6}{XL}^{2}w_{2}^{8}} - {108L_{2}^{4}{XL}^{4}w_{2}^{6}} +} \\{{8L_{2}^{2}w_{2}^{4}\sigma_{2}^{3}} - {9L_{2}^{2}{XL}^{2}w_{2}^{4}\sigma_{2}^{2}} + {108L_{2}^{4}{XL}^{2}w_{2}^{6}\sigma_{2}}}\end{pmatrix}}}}{2} +} \\{\sigma_{3}^{2} + {27L_{2}^{4}{XL}^{2}w_{2}^{4}} + \frac{27L_{2}^{2}{XL}^{2}w_{2}^{2}\sigma_{2}}{2}}\end{pmatrix}^{1/3}$   σ₂ = −σ₃ + R₂₂² + 2R₂₂RL + RL² + XL²  σ₃ = 2L₂²w₂² $\mspace{20mu}{{z\; 2} = {- \frac{\begin{matrix}{{2\; R_{22}{RL}} + \sigma_{1} + R_{22}^{2} + {RL}^{2} + {XL}^{2} - \sigma_{3} +} \\\frac{\sigma_{2}^{2} + {9L_{2}^{2}{XL}^{2}w_{2}^{2}}}{\sigma_{1}}\end{matrix}}{3L_{2}{XL}}}}$$\sigma_{1} = {\left( {{- \frac{1}{2}} + \frac{\sqrt{3}i}{2}} \right) \cdot \begin{pmatrix}{\frac{\sqrt{27L_{2}^{2}{{XL}^{2}\begin{pmatrix}{{108L_{2}^{6}{XL}^{2}w_{2}^{8}} - {108L_{2}^{4}{XL}^{4}w_{2}^{6}} +} \\\begin{matrix}{{8L_{2}^{2}w_{2}^{4}\sigma_{2}^{3}} - {9L_{2}^{2}{XL}^{2}w_{2}^{4}\sigma_{2}^{2}} +} \\{108L_{2}^{4}{XL}^{2}w_{2}^{6}\sigma_{2}}\end{matrix}\end{pmatrix}}}}{2} +} \\{\sigma_{2}^{3} + {27L_{2}^{4}w_{2}^{4}} + \frac{27L_{2}^{2}{XL}^{2}w_{2}^{2}\sigma_{2}}{2}}\end{pmatrix}^{1/3}}$   σ₂ = −σ₃ + R₂₂² + 2R₂₂RL + RL² + XL²  σ₃ = 2L₂²w₂² $\mspace{20mu}{z_{3} = {{- \frac{\begin{matrix}{{2R_{22}{RL}} - \sigma_{1} + R_{22}^{2} + {RL}^{2} + {XL}^{2} - \sigma_{3} -} \\\frac{\sigma_{2}^{2} + {9L_{2}^{2}{XL}^{2}w_{2}^{2}}}{\sigma_{1}}\end{matrix}}{3L_{2}{XL}}}\mspace{14mu}{where}}}$$\sigma_{1} = {\left( {\frac{1}{2} + \frac{\sqrt{3}i}{2}} \right) \cdot \begin{pmatrix}{\frac{\sqrt{27L_{2}^{2}{{XL}^{2}\begin{pmatrix}\begin{matrix}{{108L_{2}^{6}{XL}^{2}w_{2}^{8}} - {108L_{2}^{4}{XL}^{4}w_{2}^{6}} +} \\{{8L_{2}^{2}w_{2}^{4}\sigma_{2}^{3}} - {9L_{2}^{2}{XL}^{2}w_{2}^{4}\sigma_{2}^{2}} +}\end{matrix} \\{108L_{2}^{4}{XL}^{2}w_{2}^{6}\sigma_{2}}\end{pmatrix}}}}{2} +} \\{\sigma_{2}^{3} + {27L_{2}^{4}w_{2}^{4}} + \frac{27L_{2}^{2}{XL}^{2}w_{2}^{2}\sigma_{2}}{2}}\end{pmatrix}^{1/3}}$   σ₂ = −σ₃ + R₂₂² + 2R₂₂RL + RL² + XL²  σ₃ = 2L₂²w₂²

With XL=0, the optimum w can be shown as below:

$\begin{matrix}{{{w\_ opt}{\_\theta}\;{XL\_\theta}\; R\; 12} = \frac{\sqrt{2}L_{2}w_{2}^{2}}{\sqrt{{2L_{2}^{2}w_{2}^{2}} - R_{22}^{2} - {2R_{22}{RL}} - {RL}^{2}}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

And the corresponding efficiency is:

$\begin{matrix}{{{EffX\_ max}{\_ wopt}\_ 0R\; 12} = {- \frac{4.{L_{1}.L_{2}^{3}.{RL}.k^{2}.w_{2}^{4}}}{\begin{matrix}{\left( {R_{22} + {RL}} \right).} \\\begin{pmatrix}\begin{matrix}{{{- 4.}{L_{1}.L_{2}^{3}.k^{2}.w_{2}^{4}}} - {4.{R_{11}.L_{2}^{2}.R_{22}.w_{2}^{2}}} -} \\{{4.R_{11}{L_{2}^{2}.{RL}.w_{2}^{2}}} + {R_{11}.R_{22}^{3}} + {3.{R_{11}.R_{22}^{2}.{RL}}} +}\end{matrix} \\{{3.{R_{11}.R_{22}.{RL}^{2}}} + {R_{11}.{RL}^{3}}}\end{pmatrix}\end{matrix}}}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack\end{matrix}$

As can be observed, the optimum w is independent of w1 and the optimum wis larger than w2. Therefore, one can use what's discovered above toidentify optimum operating angular frequency w (for maximum systemefficiency) for a wireless power system. The same derivation can beexpanded to cover the case between 1 PTDU and multiple PRDU/RU. Thesystem with the optimum w requires less tuning during manufacturing timesince there is less constrain on resonant frequency of resonators andthe system can continue to function if f1 and f2 shift because ofvariety of reasons.

Using the information disclosed above, the system can determine anoptimal driving frequency and a corresponding driving voltage VPA forthe power transfer. The system monitors the emission of electromagneticwaves and detects changes from the environment, such as impedancechange. The system continuously adjusts the driving frequency and thedriving voltage VPA according to the changes detected and the dataexchange between the PRDU and the PTDU.

FIG. 5 illustrates a process 500 for starting the power transfer. Beforethe power transfer begins, the PTDU 114 sends out a probe, step 502, ifa potential PRDU is detected, step 504, the PTDU 114 sends a powerbeacon, step 506. The presence of a potential PRDU can be detected bychecking the impedance detected by the PTDU 114. A suitable device,ready to receive electrical power, will respond to the power beacon,which will be received by the PTDU 114, step 508. The PTDU 114 retrievesand examines the profile, step 509. If the device is previously known,the PTDU 114 will set up the transfer parameters according to thedevice's profile, step 510; if the device is previously unknown, thePTDU 114 will create a profile for the device, step 512. If the PTDU 114does not receive the expected response to the power beacon, the PTDU 114will treat it as a foreign object, step 514.

In some special setting, it may be possible to have two PRDUs workingwith one single PTDU. The presence of another PRDU would reduce theenergy received by each PRDU. The second PRDU will operate without theneed for the PTDU to send another power beacon.

FIG. 6 illustrates an operating process 600 of a system according to oneembodiment of the present invention. Previously described the initialemission of a power probe and a power beacon will not be repeated here.The PTDU 114 emits electromagnetic waves, step 602, and a PRDU 108receives the electromagnetic waves and converts the electromagneticwaves into electricity for storage or for consumption. The PRDU 108sends data back to the PTDU 114 and the data relates to the status ofthe power transfer. The data may indicate amount of the electricityreceived so far and this data is saved by the PTDU 114.

The PTDU 114 may detect a foreign object, step 604, by comparing thedata received from the PRDU 108. When a foreign object is present nearthe power transfer setting, if the object is metallic, it may absorbpart of the energy radiated by the electromagnetic waves, thus reducingthe amount of the energy for the PRDU 108. The metallic foreign objectmay heat up by being exposed to the electromagnetic waves, thus creatinga dangerous condition. The foreign object may also be detected when thePTDU detects change in impedance in emission of electromagnetic waves ordrop of signal strength in the signal from the communication channel tothe PRDU. The foreign object may also be detected when the data receivedback from the PRDU 108 indicates that the pace of the electricityreceived by the PRDU 108 has decreased beyond a certain threshold. Thethreshold may be set according to the profile of the receiving PRDU.

If the PTDU 114 recognizes the object, step 606, the PTDU 114 retrievesthe data received and compares with the profiles in a database, step608. If the object is a known object, the profile is retrieved, step610, and the PTDU 114 can adjust its setting according to the profile.The PTDU 114 tracks the wireless power transfer, step 612, by recordingthe data received from the object and updates the profile accordingly.If the object is not known previously, a profile will be created, step614.

If the object is a foreign object, the PTDU 114 determines whether it isa known foreign object, step 616. A foreign object may be classifiedinto different categories by checking the strength of the communicationsignal, the impact on the impedance in emission of electromagnetic wavesover time, the impact on the impedance in emission of electromagneticwaves over the frequency, the impact on the efficiency over time, theimpact on the efficiency over frequency, and/or the impact on thewaveform at resonator over time. If it is a known object, the PTDU 114will determine whether it is safe to continue the wireless powertransfer, step 624. If it is not safe to continue, the PTDU 114 willissue an alarm, step 620, and the emission of electromagnetic waves willstop, step 622. If the foreign object is not known previously, the PTDU114 will record the characteristics of the foreign object, step 618, andproceeds to issue the alarm and stops the emission of electromagneticwaves.

FIG. 7 is a diagram 700 of a PTDU 702. A control function is installedin the storage unit 712 and executed by the controller 708. Thecontroller 708 sets up the resonator 704 as the emitter ofelectromagnetic waves and the controller 708 may adjust the drivingparameters for the resonator 708, thus affecting the characteristics ofthe electromagnetic waves. The power conversion unit 710 converts theelectricity received from an external power source into electromagneticwaves and then the electromagnetic waves are emitted by the resonator704. The controller 708 also communicates with a server to retrieve theprofiles according to the data received from the PRDU. The controller708 uses the communication unit 706 to exchange the data with the PRDU.The PTDU also includes a guidance unit 714. The guidance unit 714 usesthe environment information received by the PTDU during the operation tocalculate and guide the PRDU to a best positioning relative to the PTDU.Conversely, the position of the PTDU can also be moved according to theinformation from the guidance unit 714. The PTDU is aware of thedistance and orientation between the PTDU and PRDU based on theenvironment variables, such as impedance to emission of electromagneticwaves. The guidance unit 714 provides directional guidance through avisual display to a user. Alternatively, the directional guidance canalso be issued through other means, such as audible guidance. The bestposition for the PRDU can be expressed as follows:

Position(x,y)=function(Z,dS,{acute over (η)},Q);

where Z is impedance from the environment,

-   -   dS is change of signal strength,    -   {acute over (η)} is efficiency, and    -   Q is quality factor.

The change in the relative position between the PRDU and the PRDUchanges is reflected by change in all the parameters presented earlier,which includes impedance (Z), change of signal strength (dS), efficiency({acute over (η)}), and quality factor (Q). The change in efficiency maybe represented by a loss in the quality factor (Q value). The Q valuerepresents non-dissipating energy/dissipating energy. If there is a lossin the system, the Q value for the system drops. In the context of theposition adjust process, the different relative positions between thePTDU and the PRDU introduce different Q's. The different relativepositions between the PTDU and the PRDU will also cause (1) change ofthe signal strength received by the other party, (2) change ofefficiency because different power will be received by the PRDU, and (3)change of impedance sensed by the PTDU.

FIG. 8 is a diagram 800 of a PRDU 802. A control function is installedin the storage unit 812 and executed by the controller 808. Thecontroller 808 sets up the resonator 804 as the receiver of theelectromagnetic waves. The controller 808 communicates with the PTDU.The controller 808 uses the communication unit 806 to exchange the datawith the PTDU and also with the device 104. When the PRDU 802 receivesthe electromagnetic waves and the power conversion unit 810 converts theenergy received through the electromagnetic waves into either AC or DCfor consumption by a load.

FIG. 9 is a flowchart 900 of the position adjustment process. While thePTDU emits electromagnetic waves, step 902, the PTDU monitors theenvironment data and the data received from the PRDU, step 904. The PRDUis placed initially around the PTDU and changes of signal strength,efficiency, impedance, and the Q value are recorded. A mappinginformation between relative positions and change of efficiency, signalstrength, impedance, and Q value is obtained, step 908. Using thismapping information, the PTDU can provide directional guidance forproper physical alignment between the PTDU and the PRDU, step 910.

FIG. 10 is a flowchart 1000 continuous adjustment of driving parametersof electromagnetic waves. During a wireless power transfer, the PTDUemits electromagnetic waves, step 1002, and monitors the environmentdata and the data received from the PRDU, step 1004. If a change inefficiency is detected, step 1006, the PTDU recalculates the drivingparameters, step 1008, and uses these recalculated driving parameters toadjust the emission of the electromagnetic waves, step 1010. The changein efficiency may be caused by many factors, such as introduction offoreign objects or changes in relative positioning of the PTDU and thePRDU among others.

FIG. 11 is an illustration 2000 of the interface between a PTDU and aPRDU according to another embodiment of the invention. In theembodiment, the PRDU 1080 may receive electromagnetic waves from thePTDU 1140 and supplies the electrical power to a load device 1040. Asshown in FIG. 11, the PRDU 1080 may comprise a resonator 2040, a powerconversion circuit 2020 (e.g. an AC/DC power converter), a controller(not shown), a communication unit 2060, and a power throttling circuit2140. The PRDU 1080 can be applied to the PRDU 106 and PRDU 108 of FIG.1 and PRDU 802 of FIG. 8. In the embodiment, the resonator 2040 mayreceive the electromagnetic waves and convert them into alternatingcurrent (AC) (i.e. electrical power). The power throttling circuit 2140may determine how much electrical power from the resonator 2040 needs tobe transmitted to the power conversion circuit 2020 based on the powerrequirement of the load device 1040. In the embodiment, the electricalpower which needs to be transmitted to the power conversion circuit 2020may be regarded as a target power to power the load device 1040. Afterthe power throttling operation, the power throttling circuit 2140 maytransmit the target power to the power conversion circuit 2020. Afterreceiving the target power required for the load device 1040, the powerconversion circuit 2020 may convert the AC corresponding to the targetpower into direct current (DC). The DC is then made available to a loaddevice 1040. The DC may be used directly by the load device 1040 or itmay be used to charge a storage unit inside the load device 1040. Thecommunication unit 2060 may send and receive data to and from the loaddevice 1040. The communication unit 2060 may also send the data receivedfrom the load device 1040 to the PTDU 1140 and the data is sentwirelessly to the PTDU 1140 as out-of-band communication. In anotherembodiment, the power throttling circuit 2140 may be allocated in a RU(e.g. RU 110). It should be noted that the power throttling circuit 2140is only used to illustrate the embodiments of the invention, but theinvention should not be limited thereto. In one embodiment, the powerthrottling circuit may be configured in each PRDU or configured in eachRU. In another embodiment, the power throttling circuit may beconfigured in each PRDU and each RU.

In the embodiment, the PTDU 1140 may receive electrical power from apower source and transmit the power through electromagnetic waves to thePRDU 1080. As shown in FIG. 11, the PTDU 1140 has a resonator 2100, aDC/AC power converter 2120, a controller (not shown), and acommunication unit 2080. The PTDU 1140 can be applied to PTDU 112 andPTDU 114 of FIG. 1 and PTDU 702 of FIG. 7. In the embodiment, the DC/ACpower converter 2120 may convert the DC into AC that drives theresonator 2100. The PTDU 1140 also may receive the AC directly. Theresonator 2100 may receive the AC and generate electromagnetic waves.The communication unit 2080 receives the data transmitted wirelessly bythe PRDU 1080. There are basically two types of data exchanged betweenthe PTDU 1140 and the PRDU 1080: power control information and userdata. The PTDU 1140 may receive the power control data from the PRDU1080, so the PTDU 1140 can be properly set up for the power transfer.The PTDU 1140 may send status information back to the PRDU 1080. Theuser data from the applications running on the device 1040 are sent fromthe PRDU 1080, through the PTDU 1140, to servers connected to theInternet. The user data from the applications running on the serversconnected to the Internet are sent from the PTDU 1140, through the PRDU1080, to the device 1040.

The resonator 2040 in the PRDU 1080 has a resonant frequency f2 and theresonator 2100 in the PTDU 1140 has a resonant frequency f1. Theresonant frequency f1 may be different from the resonant frequency f2.The resonator 2100 in the PTDU 1140 is driven by a voltage VPA from theDC/AC power converter 2120 operating at frequency fs. The PTDU 1140 candetermine the best operating frequency fs for the DC/AC power converter2120, such that there is no relationship between the frequencies f1 andf2, the frequency fs is independent from frequency f1, and the frequencyfs is higher than frequency f2.

Traditionally power transfer between the PTDU 1140 and the PRDU 1080 isaccomplished through resonant inductive coupling, where the resonatorsin the PTDU 1140 and the PRDU 1080 are tuned to resonate at a resonantfrequency and the resonant frequency is the same as or close to theresonant frequency of each PTDU and PRDU. The smart algorithm,introduced by the present invention, running on the PTDU 1140 can findthe best operating frequency fs, along with proper adjustment of thedriving voltage VPA and the driving frequency to deliver power with goodsystem efficiency and there is no requirement for the operatingfrequency (also known as the driving frequency) fs to be close to or thesame as the resonant frequencies f1 and f2. The operating frequency fsis independent of the resonant frequency f1 and also higher than theresonant frequency f2. This algorithm can handle dynamic load change anddistance change by adjusting the operating frequency fs and/or drivingvoltage VPA.

When in use, the system of the present invention not only enableswireless charging of a mobile device but also provides electricity to aremote electric apparatus, such as a production machine in a factory.The production machine may be equipped with communication capabilitiessuch as smart devices. Through use of a repeater unit, a PTDU can reacha PRDU located at a distant location in a factory setting. When theproduction machine is connected to the PRDU, the PTDU can detect thepresence of the production machine and retrieve the profile for theproduction machine. The profile may indicate the duty cycle, the VPA,the frequency for the production machine, and past usage data amongother information. If the PTDU learns from the profile that theproduction machine is generally operated in the afternoon and demands anX amount of power for a Y period of time, then the PTDU can adjustitself to emit electromagnetic waves during the afternoon for the Yperiod and for the X amount of power. The PTDU tailors its operationbased on the profile for the production machine and the PTDU will updatethe profile with the data received from the PRDU and the productionmachine.

During the operation, the system continues to monitor the environmentinformation from the PTDU and the information received from the PRDU andthe load (smart device and/or production machine). If the system detectsthat the relative distance between the PTDU and the PRDU have changed,the system will adjust the parameters for driving the emission ofelectromagnetic waves such as VPA and/or the driving frequency fs.

If a smart device equipped with a PRDU is placed adjacent to a PTDU forwireless powering purpose, the PTDU emits electromagnetic waves and alsoestablishes a data link to the PRDU. While the smart device is beingpowered wirelessly by the PTDU, the user application on the smart devicecan communicate with servers on the Internet.

Although the present invention has been described with reference to thepreferred embodiments, it will be understood that the invention is notlimited to the details described thereof. Various substitutions andmodifications have been suggested in the foregoing description, andothers will occur to those of ordinary skill in the art. Therefore, allsuch substitutions and modifications are intended to be embraced withinthe scope of the invention as defined in the appended claims. It isunderstood that features shown in different figures and described indifferent embodiments can be easily combined within the scope of theinvention. It is also understood that the components of the systemdisclosed in this specification may be implemented through combinationof software and hardware. The load described in the presentspecification may be a smart device or any other electrical apparatus.

Modifications, additions, or omissions may be made to the systems andmethods described without departing from the scope of the disclosure.The components of the systems and methods described may be integrated orseparated according to particular needs. Moreover, the operations of thesystems and methods described may be performed by more, fewer, or othercomponents without departing from the scope of the present disclosure.

Although the present disclosure has been described with severalembodiments, sundry changes, substitutions, variations, alterations, andmodifications can be suggested to one skilled in the art, and it isintended that the disclosure encompass all such changes, sub stitutions,variations, alterations, and modifications falling within the spirit andscope of the appended claims.

What is claimed is:
 1. A system for providing electrical power to a load device through wireless transmission, comprising: a power transmitting data unit (PTDU) receiving electrical power from a power source; at least one power receiving data unit (PRDU), connected to the load device, wherein the PRDU further comprises: a resonator, receiving electromagnetic waves from the PTDU and converting the electromagnetic waves into the electrical power; and a power conversion circuit, providing a target power to the load device, wherein the electrical power required for the load device is regarded as the target power; and at least one power throttling circuit, determining how much electrical power from the resonator needs to be transmitted to the power conversion circuit based on a power requirement of the load device.
 2. The system of claim 1, wherein the power throttling circuit is allocated in the PRDU and the power throttling circuit is coupled to the resonator and the power conversion circuit.
 3. The system of claim 1, further comprising: at least one repeater unit (RU), receiving the electromagnetic waves from the PTDU and transmitting the electromagnetic waves to the PRDU.
 4. The system of claim 3, wherein the power throttling circuit is allocated in the RU.
 5. The system of claim 1, further comprising: a remote power-profile artificial-intelligence (AI) engine, storing first power profiles, wherein the first power profiles stored by the remote power-profile AI engine are shared with a power-profile AI engine of the PTDU and second power profiles obtained by the power-profile AI engine of the PTDU are shared with the remote power-profile AI engine.
 6. The system of claim 5, wherein the first power profiles and the second power profiles comprise setup information for the load device, the PRDU and the PTDU, identification data for the load device, past power transfer information, a duty cycle, a driving voltage, a driving frequency, and past usage data.
 7. The system of claim 1, further comprising: a remote foreign object detection (FOD) AI engine, recognizing foreign objects, wherein information related to the recognition or detection of foreign objects obtained by the remote FOD AI engine are shared with a FOD AI engine of the PTDU and information related to the recognition or detection of foreign objects obtained by the PTDU are shared with the remote FOD AI engine and the PTDU.
 8. The system of claim 7, wherein the foreign objects are classified into different categories based on a strength of a communication signal, impact on an impedance in emission of the electromagnetic waves, impact on efficiency over frequency, impact on efficiency over time, and/or impact on a waveform at a resonator over time.
 9. The system of claim 1, wherein the PTDU comprises a guidance unit, wherein the guidance unit is configured to use environment information received by the PTDU to calculate and guide the PRDU to a best positioning relative to the PTDU.
 10. A method for providing electrical power to a load device through wireless transmission, wherein the method is applied to a system which comprises a power transmitting data unit (PTDU), at least one power receiving data unit (PRDU) and at least one power throttling circuit, comprising: receiving by a resonator of the PRDU, the electromagnetic waves from the PTDU and converting the electromagnetic waves into electrical power; determining, by the power throttling circuit, how much electrical power from the resonator needs to be transmitted to a power conversion circuit of the PRDU based on a power requirement of the load device, wherein the electrical power required for the load device is regarded as a target power; and providing, by the power conversion circuit, the target power to the load device.
 11. The method of claim 10, wherein the power throttling circuit is allocated in the PRDU.
 12. The method of claim 10, wherein the system further comprises at least one repeater unit (RU), wherein the RU receives the electromagnetic waves from the PTDU and transmits the electromagnetic waves to the PRDU.
 13. The method of claim 12, wherein the power throttling circuit is allocated in the RU.
 14. The method of claim 10, wherein the system further comprises a remote power-profile artificial-intelligence (AI) engine, wherein the remote power-profile AI engine stores first power profiles, wherein the first power profiles stored by the remote power-profile AI engine are shared with a power-profile AI engine of the PTDU and second power profiles obtained by the power-profile AI engine of the PTDU are shared with the remote power-profile AI.
 15. The method of claim 14, wherein the first power profiles and the second power profiles comprise setup information for the load device, the PRDU and the PTDU, identification data for the load device, past power transfer information, a duty cycle, a driving voltage, a driving frequency, and past usage data.
 16. The method of claim 10, wherein the system further comprises a remote foreign object detection (FOD) AI engine, wherein the remote FOD AI engine recognizes foreign objects, wherein information related to the recognition or detection of foreign objects obtained by the remote FOD AI engine are shared with a FOD AI engine of the PTDU and information related to the recognition or detection of foreign objects obtained by the FOD AI engine of the PTDU are shared with the remote FOD AI engine.
 17. The method of claim 16, wherein the foreign objects are classified into different categories based on a strength of a communication signal, impact on an impedance in emission of the electromagnetic waves, impact on efficiency over frequency, impact on efficiency over time, and/or impact on a waveform at a resonator over time.
 18. The method of claim 10, wherein the PTDU comprises a guidance unit, wherein the guidance unit is configured to use environment information received by the PTDU to calculate and guide the PRDU to a best positioning relative to the PTDU. 